           (codec/url-decode (or val "") encoding))
          param-map))
     {}
-    (str/re-split #"&" param-string)))
+    (string/split param-string #"&")))
 
 (defn- assoc-query-params
   "Parse and assoc parameters from the query string with the request."

  [request encoding]
  (merge-with merge request
    (if-let [body (and (urlencoded-form? request) (:body request))]
      (let [params (parse-params (duck/slurp* body) encoding)]
        {:form-params params, :params params})
      {:form-params {}, :params {}})))


(ns ring.middleware.params
  "Parse form and query params."
  (:require [ring.util.codec :as codec]
            [clojure.string :as string]
            [clojure.contrib.io :as io]))

(defn assoc-param
  "Associate a key with a value. If the key already exists in the map,
